package com.kuang.pc;

import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

/**
 * Author: Zhang Dongwei
 * Date: 2022/3/13 11:54
 */
public class B {
    public static void main(String[] args) {
        Data2 data = new Data2();

        new Thread(()->{
            for (int i = 0; i< 10; i++){
                try {
                    data.increment();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }, "A").start();

        new Thread(()->{
            for (int i = 0; i< 10; i++){
                try {
                    data.decrement();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }, "B").start();

        new Thread(()->{
            for (int i = 0; i< 10; i++){
                try {
                    data.increment();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }, "C").start();

        new Thread(()->{
            for (int i = 0; i< 10; i++){
                try {
                    data.decrement();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }, "D").start();

    }
}

// 判断等待，业务，通知
class Data2{// 数字，资源类

    private int number = 0;

    Lock lock = new ReentrantLock();
    Condition condition = lock.newCondition();
//    condition.await();//等待
//    condition.signalAll();//唤醒全部

    //+1
    public void increment() throws InterruptedException {
        try {
            lock.lock();
            //业务代码写在这里
            while (number!=0){
                //等待
                condition.await();
            }
            number ++;
            System.out.println(Thread.currentThread().getName()+"=>"+number);
            //通知其他线程，我+1完毕了
            condition.signalAll();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }

    }

    //-1
    public  void decrement() throws InterruptedException {
        try {
            lock.lock();
            while (number == 0){
                //等待
                condition.await();
            }
            number --;
            System.out.println(Thread.currentThread().getName()+"=>"+number);
            //通知其他线程，我-1完毕了
            condition.signalAll();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }
}
